2001 INFINITI QX4 IDX

5 CHECK SHIFT UP (D3TO D4)
Does A/T shift from D3to D4at the specified speed?
YesorNo
Ye s©GO TO 9.
No©Check control valve again. Repair or replace control valve assembly.
6 CHECK LINE PRESSURE SOLENOID VALVE
1. Remove control valve assembly. Refer to AT-273.
2. Refer to ªComponent Inspectionº, AT-147.
SAT158J
OK or NG
OK©GO TO 7.
NG©Replace solenoid valve assembly.
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DTC P0734 IMPROPER SHIFTING TO 4TH GEAR POSITION
Diagnostic Procedure (Cont'd)
AT-145

SAT159J
Component InspectionNBAT0050SOLENOID VALVESNBAT0050S01IFor removal, refer to AT-273.
Resistance CheckNBAT0050S0101ICheck resistance between terminals (3, 2 or 6) and ground.
Solenoid valve Terminal No. Resistance (Approx.)
Shift solenoid valve A 3
Ground20-40W
Shift solenoid valve B 2
Line pressure solenoid valve 6 2.5 - 5W
SAT158J
Operation CheckNBAT0050S0102ICheck solenoid valve by listening for its operating sound while
applying battery voltage to the terminals (3, 2 or 6) and ground.
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DTC P0734 IMPROPER SHIFTING TO 4TH GEAR POSITION
Component Inspection
AT-147

SAT014K
SAT020K
DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION
PROCEDURE
NBAT0051S01NOTE:
If ªDIAGNOSTIC TROUBLE CODE CONFIRMATION PROCE-
DUREº has been previously conducted, always turn ignition
switch ªOFFº and wait at least 5 seconds before conducting
the next test.
After the repair, perform the following procedure to confirm the
malfunction is eliminated.
With CONSULT-II
1) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode for ªENGINEº with CON-
SULT-II and wait at least 1 second.
With GST
Follow the procedure ªWith CONSULT-IIº.
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DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE
Description (Cont'd)
AT-149

Diagnostic ProcedureNBAT0052
1 CHECK VALVE RESISTANCE
1. Turn ignition switch to ªOFFº position.
2. Disconnect terminal cord assembly connector on the right side of transfer assembly.
3. Check resistance between terminal 7 and ground.
SAT156J
Is resistance approx. 10 - 20W?
Ye s©GO TO 3.
No©GO TO 2.
2 CHECK VALVE OPERATION
1. Remove oil pan. Refer to AT-273.
2. Check the following items:
ITorque converter clutch solenoid valve
Refer to ªComponent Inspectionº, AT-152.
IHarness of terminal cord assembly for short or open
OK or NG
OK©GO TO 3.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
3 CHECK RESISTANCE
1. Turn ignition switch to ªOFFº position.
2. Disconnect TCM harness connector.
3. Check resistance between terminal 7 and TCM harness connector terminal 3. Refer to wiring diagram Ð AT Ð TCV.
Continuity should exist.
If OK, check harness for short to ground and short to power.
4. Reinstall any part removed.
OK or NG
OK©GO TO 4.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
4 CHECK DTC
Perform Diagnostic Trouble Code (DTC) confirmation procedure, AT-149.
OK or NG
OK©INSPECTION END
NG©GO TO 5.
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DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE
Diagnostic Procedure
AT-151

DescriptionNBAT0054IThis is an OBD-II self-diagnostic item and not available in TCM
self-diagnosis.
IThis malfunction will not be detected while the O/D OFF indi-
cator lamp is indicating another self-diagnosis malfunction.
IThis malfunction is detected when the A/T does not shift into
fourth gear position or the torque converter clutch does not
lock up as instructed by the TCM. This is not caused by elec-
trical malfunction (circuits open or shorted) but by mechanical
malfunction such as control valve sticking, improper solenoid
valve operation, malfunctioning oil pump or torque converter
clutch, etc.
CONSULT-II REFERENCE VALUE IN DATA MONITOR
MODE
NBAT0054S02Remarks: Specification data are reference values.
Monitor item Condition Specification
Torque converter clutch
solenoid valve dutyLock-up ªOFFº
"
Lock-up ªONºApproximately 4%
"
Approximately 94%
Line pressure solenoid
valve dutySmall throttle opening (Low line pressure)
"
Large throttle opening (High line pressure)Approximately 24%
"
Approximately 95%
TCM TERMINALS AND REFERENCE VALUENBAT0054S03Remarks: Specification data are reference values.
Terminal
No.Wire color Item ConditionJudgement
standard
(Approx.)
1GYLine pressure
solenoid valve
When releasing accelerator pedal after warm-
ing up engine.1.5 - 3.0V
When depressing accelerator pedal fully after
warming up engine.0V
2 BR/YLine pressure
solenoid valve
(with dropping
resistor)When releasing accelerator pedal after warm-
ing up engine.5 - 14V
When depressing accelerator pedal fully after
warming up engine.0V
3 G/ORTorque converter
clutch solenoid
valve
When A/T performs lock-up. 8 - 15V
When A/T does not perform lock- up. 0V
ON BOARD DIAGNOSIS LOGICNBAT0054S04This diagnosis monitors actual gear position by checking the torque
converter slip ratio calculated by TCM as follows:
Torque converter slip ratio = A x C/B
A: Output shaft revolution signal from revolution sensor
B: Engine speed signal from ECM
C: Gear ratio determined as gear position which TCM supposes
If the actual gear position is much lower than the position (4th)
supposed by TCM, the slip ratio will be much less than normal. In
case the ratio does not reach the specified value, TCM judges this
diagnosis malfunction.
This malfunction will be caused when shift solenoid valve B is stuck
closed.
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DTC P0744 IMPROPER LOCK-UP OPERATION
Description
AT-153

IIf ªTESTINGº does not appear on CONSULT-II for a long
time, select ªSELF-DIAG RESULTSº. In case a 1st trip DTC
other than P0744 is shown, refer to applicable ªTROUBLE
DIAGNOSIS FOR DTCº.
5) Make sure that ªOKº is displayed. (If ªNGº is displayed, refer
to ªDIAGNOSTIC PROCEDUREº.)
Refer to ªDIAGNOSTIC PROCEDUREº, AT-157.
Refer to shift schedule, AT-356.
With GST
Follow the procedure ªWith CONSULT-IIº.
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DTC P0744 IMPROPER LOCK-UP OPERATION
Description (Cont'd)
AT-155

Diagnostic Procedure=NBAT0055
1 CHECK SHIFT UP (D3TO D4)
During ªCruise test þ Part 1º, AT-71.
Does A/T shift from D
3to D4at the specified speed?
SAT988H
YesorNo
Ye s©IGO TO 10.
IAnd check for proper lock-up.
No©GO TO 2.
2 CHECK LINE PRESSURE
Perform line pressure test. Refer to AT-62.
OK or NG
OK©GO TO 3.
NG©GO TO 6.
3 CHECK CONTROL VALVE
1. Disassemble control valve assembly. Refer to AT-301.
2. Check to ensure that:
IValve, sleeve and plug slide along valve bore under their own weight.
IValve, sleeve and plug are free from burrs, dents and scratches.
IControl valve springs are free from damage, deformation and fatigue.
IHydraulic line is free from obstacles.
SAT367H
OK or NG
OK©GO TO 4.
NG©Repair control valve.
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DTC P0744 IMPROPER LOCK-UP OPERATION
Diagnostic Procedure
AT-157

7 CHECK CONTROL VALVE
1. Disassemble control valve assembly. Refer to AT-301.
2. Check line pressure circuit valves for sticking.
IPressure regulator valve
IPilot valve
IPressure modifier valve
SAT367H
OK or NG
OK©GO TO 8.
NG©Repair control valve.
8 CHECK SHIFT UP (D3TO D4)
Does A/T shift from D3to D4at the specified speed?
YesorNo
Ye s©GO TO 9.
No©Check control valve again. Repair or replace control valve assembly.
9 CHECK DTC
Perform Diagnostic Trouble Code (DTC) confirmation procedure, AT-154.
OK or NG
OK©INSPECTION END
NG©IGO TO 10.
IAnd check for proper lock-up.
10 CHECK LOCK-UP CONDITION
During ªCruise test þ Part 1º, AT-71.
Does A/T perform lock-up at the specified speed?
YesorNo
Ye s©Perform ªCruise test þ Part 1º again and return to the start point of this flow chart.
No©GO TO 11.
11 CHECK TORQUE CONVERTER CLUTCH SOLENOID VALVE
1. Remove control valve assembly. Refer to AT-273.
2. Check torque converter clutch solenoid valve operation.
Refer to AT-161.
OK or NG
OK©GO TO 12.
NG©Replace solenoid valve assembly.
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DTC P0744 IMPROPER LOCK-UP OPERATION
Diagnostic Procedure (Cont'd)
AT-159